freebsd-dev/sys/opencrypto/crmbuf.c

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/*
* Copyright (c) 2002 Somebody. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include "opt_param.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
/*
* Miscellaneous mbuf routines that belong in uipc_mbuf.c but
* are kept private to the crypto support for now.
*/
extern int m_apply(struct mbuf *m, int off, int len,
int (*f)(caddr_t, caddr_t, unsigned int), caddr_t fstate);
extern struct mbuf * m_getptr(struct mbuf *m, int loc, int *off);
/*
* Apply function f to the data in an mbuf chain starting "off" bytes from the
* beginning, continuing for "len" bytes.
*/
int
m_apply(struct mbuf *m, int off, int len, int (*f)(caddr_t, caddr_t, unsigned int), caddr_t fstate)
{
int rval;
unsigned int count;
if (len < 0)
panic("m_apply: len %d < 0", len);
if (off < 0)
panic("m_apply: off %d < 0", off);
while (off > 0) {
if (m == NULL)
panic("m_apply: null mbuf in skip");
if (off < m->m_len)
break;
off -= m->m_len;
m = m->m_next;
}
while (len > 0) {
if (m == NULL)
panic("m_apply: null mbuf");
count = min(m->m_len - off, len);
rval = f(fstate, mtod(m, caddr_t) + off, count);
if (rval)
return (rval);
len -= count;
off = 0;
m = m->m_next;
}
return (0);
}
/*
* Return a pointer to mbuf/offset of location in mbuf chain.
*/
struct mbuf *
m_getptr(struct mbuf *m, int loc, int *off)
{
while (loc >= 0) {
/* Normal end of search */
if (m->m_len > loc) {
*off = loc;
return (m);
}
else {
loc -= m->m_len;
if (m->m_next == NULL) {
if (loc == 0) {
/* Point at the end of valid data */
*off = m->m_len;
return (m);
}
else
return (NULL);
}
else
m = m->m_next;
}
}
return (NULL);
}